صور الصفحة
PDF
النشر الإلكتروني
[graphic][graphic]

THE LIBRARY
OF THE

UNIVERSITY OF ILLINOIS

in the Martens or Cats, in which the fosses are evanescent ;* the auditory cavities very small; the olfactory cavities moderate; the frontal sinuses large; the palatal bones curved convexly, and the rami of the lower jaw as much concavely; the coronoid processes of the latter enormous and inclined forwards; the bones of the scull in general thick and massive; proportion of the face to the rest of the scull, as one-third.

Teeth. The dental formula is . 1:.:: but the first pair of the lower jaw are deciduous, and, in old animals especially, the molars are (I write with fine samples before me) more frequently. The incisors are close together and ranged nearly in a straight line to the front, those of the lower jaw touching the canines, whilst those of the upper jaw are separated therefrom by the usual interval for the passage of the lower canines. The exterior incisors of the upper jaw are larger than the rest, and are as much scarped externally as are the lower canines internally, by reason of that friction of the one against the other which is caused by the high lateral action of the jaws. Canines small, conic, little curved, faintly grooved lengthwise, the upper insulated, the lower in contact with the incisors and molars. Molars divided by their characters into false and true, without any possible distinction of carnassial and tubercular teeth. Premolars 3:3, including the deciduous ones: last pair rather triturant than trenchant. True molars Upper true molars disposed transversely, squarish in form, nearly equal in size and exhibiting on their, in general, flat crowns, 3 or 4 sunken central spaces filled with the dark soft substance above alluded to, and which is bounded serpentinely by rounded rather than dentated margins of enamel and a central transverse sinuous ridge of the same. True molars of the lower jaw disposed lengthwise, narrow, parallelogramic or elliptic; the first pair smaller than the two others, which are equal; and all exhibiting central masses of crusta petrosa enveloped by a serpentine sinuous margin of enamel, as in the upper jaw nearly. In the composition, forms and action of these teeth taken together, there is little or no real resemblance to be found with the teeth of even the least carnivorous of the ordinary carnivora, such as the Bears, Badgers, and Screwtails, though it is among them that one

In the Viverrines, the fosses and the crests are both of extreme size, and the brainpan consequently much reduced. In these respects there is no resemblance with the Ailures; nor in other respects.

naturally looks for the dental prototype of Ailurus. But I apprehend that several of the genera to be presently enumerated as the probable components of the group of Cat-toed Plantigrades, will be hereafter found to exhibit a closer resemblance and more harmonious blending with the Ailurine type of dentition as of general structure.

Bony carcase.—I have not now a perfect skeleton of Ailurus to refer to; so far as I can trust my notes, the bones are as follows:- Cervical 7. Dorsal 13. Lumbar 5. Sacral 3. Caudal 22. Carpal 8. Metacarpal 5. Digital 3, for each toe fore and aft. Tarsal 9. Metatarsal 5. Ribs 13 pairs, whereof 5 pairs are false, and 11 true. The short strong and highly articulated limbs, together with the finely harmonising flexile wrists and ankles, bear an extreme resemblance to the extremities of the Martens (Flavigula*) and Screwtails, and have much similitude with those of the Bears (Helarctos) but form a complete contrast with the extremities of the Cats and of the Civets. On the other hand, the highly mobile digits, disencumbered of the palmary and plantary mass, are much more similar to those of the Cats than to those of the Bears, and bear a resemblance amounting almost to identity to the digits of the Screwtails and Martens. The 5th or internal digit is very little withdrawn from the front, and is forthcoming alike in the anteal and posteal extremities. Of the other 4 digits the 2 central are nearly equal and the 2 lateral also, but with an andromorphous bias, and the whole are united as far forward as the terminodigital pads by a highly elastic membrane, which allows the freest play to the digits. The thick socks however in which the feet of the Ailuri are completely enveloped, must impede their power of feeling and even of raptorial grasping, as compared with the paws of the Martens and Paradoxures, though the extreme mobility of the unguical phalanges still leaves the sharp and compressed talons almost as serviceable as in either of those genera. The talons of the Wáhs are as highly curved, as much compressed, and as sharp, as in the Screwtails or in the Martens, and I might add, in the Cats, for there is hardly any appreciable difference between the four genera in those respects, and

* In this animal the dorsal vertebræ (and ribs) are 14: the lumbar 7: the sacral 4: the caudal 26: the rest as in Ailurus ut supra. The teeth of Flavigula (molars) are §. It is therefore a Martes, not a Mustela.

† See accompanying sketches.

the talons of all are equally reversile over the penultimate phalanges, and equally retained there, except when required, by the strong tensor tendons, the difference of the digits consisting in this only, that those of the Martens are not at all sheathed, those of the Paradoxures and Wáhs are but half sheathed, or little more than half, and those of the Cats, completely so. This is a difference which but for the terrific energy of the Feline paw one should be disposed to underrate, and I confess that after the most careful examination of the organs I am inclined to attribute the superior force of the Feline arm's stroke to the momentum and velocity inseparable from the digitigrade structure rather than to any difference in the organization of the digits and talons, points in which it appears to me that the Ailuri, Paradoxuri and Martens are all upon a par with the Cats, or nearly so. I am aware that this is a statement at variance with the law of correlation and dependance of parts in structure. Show me,' exclaims our great master Cuvier, with the noble confidence of genius, 'show me a nail and I will show you the whole structure of the animal which bore it.' And I shall be probably told with a sneer that the Cats and Weasels are the most exclusive of blood spillers, whilst the Paradoxures are mainly, and the Ailures (according to my own account) exclusively, vegetalivorous. I can only say in reply that I endeavour faithfully to report what I have carefully examined; that he who affixed the Feline paw to the Ursine arm of Ailurus apparently delights to accomplish the same ends by very varied means; that there are many things in his systema naturæ which our's yet halts behind the comprehension of;† and that, for example, in our systems the contrast is much greater between the structures, than it is between the habits, of Ursus ferox and of Felis tigris, or of the Racoons and Coatis on one hand, and the

* I mention the Martens more frequently than the Weasels proper, because I have before me fine fresh specimens of the former; but in fact the latter agree with the former in regard to the feet.

+ The systems which associate Ailurus and Arctictis with the Bears, and dissociate Ursitaxus and Mellivora from the Bears, and range Lutra with the Seals, and Paradoxurus with the dog-like Viverræ, are surely not quite in harmony with the method of the divine designer. The Palmate foot of Lutra may be seen in Martes, Paradoxurus, &c. and the free lateral and posteal action of the hind legs of Lutra, in those genera, as well as in the Coatis, the Potos, the Wáhs, &c. So that there is no need on these accounts to sever Lutra from his old allies.

« السابقةمتابعة »